Ground mounting base for central air conditioner heat exchanger units

ABSTRACT

A ground mounting base is disclosed for use with externally mounted heat exchanger units such as the outdoor condenser unit commonly used in residential central air conditioning systems. The base is light weight but strong and comprises a pad of concrete employing vermiculite as its primary aggregate, a wire screening reinforcement, and a top layer of sand aggregate concrete. A bubble level is affixed at the top surface to aid in leveling the base and upward projecting pre-set mounting bolts affixed therein for receiving and affixing the heat exchanger to the base. The base also preferably has inclined side walls inclining outward from the top to the bottom to aid in preventing horizontal movement after implacement.

United States Patent 1191 Unger 1 1 Mar. 27, 1973 154] GROUND MOUNTINGBASE FOR CENTRAL AIR CONDITIONER HEAT EXCHANGER UNITS [76] Inventor:Robert M. Unger, 564 Northampton Cir., Elk Grove Village, 111.

22 Filed: Jan.22,1971 21 Appl.No.:108,909

[52] 11.8. C1. ..248/346, 248/19, 248/361 [51] Int. Cl ....F16m 13/0 0[58] Field of Search ..248/346, 19, 361 52/292, 295,

8/1967 Grimelli ..248/36l x Primary Examiner-Edward C. AllenAttorney-Richard Gordon Kinney [57] ABSTRACT A ground mounting base isdisclosed for use with externally mounted heat exchanger units such asthe outdoor condenser unit commonly used in residential central airconditioning systems. The base is light weight but strong and comprisesa pad of concrete employing vermiculite as its primary aggregate, a wirescreening reinforcement, and a top layer of sand aggregate concrete. Abubble level is affixed at the top surface to aid in leveling the baseand upward projecting pre-set mounting bolts affixed therein forreceiving and affixing the heat exchanger to the base. The basealsopreferably has inclined side wallsinclining outward from the top tothe bottom to aid in preventing horizontal movement after implacement.

4 Claims, Drawlng'Figure s Patented March 27, 1973 lnvenTorRoberi'MUnger By W Attorney GROUND MOUNTING BASE FOR CENTRAL AIRCONDITIONER HEAT EXCHANGER UNITS FIELD OF THE INVENTION The presentinvention relates to mounting bases for heat exchanger units of the typemounted on soil such as the common residential central air conditioningcondenser unit.

BACKGROUND OF THE INVENTION At the present time most residential centralair conditioning systems, as well as a few other systems, employexternally mounted heat exchanger unit. Such air conditioning units maycomprise a condenser, often combined with a compressor, a blower andelectric motor equipment. For our purposes, we will term all of thisequipment that is packaged to form a single unit, as a heat exchangerunitJThese units are most commonly mounted exposed to the elements butnecessarily near the residence or building with which they are employed.

They are often rather noisy since blower, fans, compressors andsimilarequipment are often included. In most cases they are made towithstand exposure to the air and elements (perhaps with a cover duringwinter) but do require a firm and level base. 1

In the past this has been a concrete pad usually square with verticalsides formed of normal concrete made of crushed stone or gravel, cementand sand, and mixed with water. To save set-up time and visits, thesepads are usually pre-cast and delivered to the site in a finished andhardened state. Although these pads generally serve their purpose well,they suffer from certain drawbacks that the present invention overcomes.These prior pads are extremely heavy and hard to handle. For example, atypical small unit pad, 3 by 4 feet by 2 inches, may weigh 125 pounds,normally-requiring two or more men to carry and handle it. Conventionalpre-cast concrete pads must be set in aproperly which pad is formed ofconcrete employing vermiculite as its primary aggregate, by volume, andincluding reinforcement therein.

In accordance with another feature of the invention the top surfacelayer is formed primarily of concrete employing sand as its primaryaggregate, by volume, to provide a rigid top surface.

In accordance with other features of the present invention the padincludes a bubble level formed therein at its top surface so that it maybe leveled quickly and easily in installation and its leveling easilychecked during use. The side walls of the base are preferably slanted orinclined outward from the top to the bottom surfaces. Pre-positionedbolts may be cast in the base so as to project from the top surface toaid in attaching the heat exchanger unit to the base. Further, theentire base surface is preferably sealed by a silicone or wax sealer.

ADVANTAGES OF THE INVENTION A soil-mounted base for a heat exchange unitmade in accordance with the present invention has light weight as itsprimary advantage. For example a base of pening. Further the basesbottom surface can deform preleveled and filled site or it may fracture.Such pads g or bases are also subject to fracture through dropping (towhich it is prone because of its weight). Proper leveling of the padonce on the ground is also difficult.

The rigid structure of the pr'e-cast conventional pad also does nothingto lessen the noise and vibration generated by the unit mounted thereonand can in certain circumstances serve as a sounding board to magnifythat noise. If set too near the building or in certain soils,undesirable vibrations of the unit can be felt in the structure or thesurrounding area.

It sometimes happens in the installation of the conventional rigidpre-cast pad that the soil is not properly prepared or later settlesunevenly. When this occurs the weight of the pad and its units canbe-concentrated at spaced horizontal points subjecting the pad to shearand strain that can lead to cracking and/or fracturing of the pad.

SUMMARY OF TI-IEINVENTION In overcoming one or more of theaforementioned disadvantages of prior bases, the present inventionprovides a new and improved external heat exchanger unit ground basecomprising at least a pad having a generally flat top surface and agenerally flat bottom surface with joining edge side walls therebetween,

to accommodate small variations in the soil thus insur-. ing betterweight distribution and less danger of cracking or fracturing dunginstallation and use.

The inclusion of a permanent bubble level provides for greater ease ofinstallation and maintenance while the inclined side walls both spreadthe weight better, resist horizontal movement of the base and-unit andalso aids in the manufacture of the base.

BRIEF DESCRIPTION OF THE DRAWINGS The features of the present inventionwhich are believed to be novel are set forth with particularity in theappended claims. The invention, together with the further advantagesthereof, may best be understood by reference to the followingdescription taken in connection with the accompanying drawings, in theseveral figures of which like reference numerals identify like elements,and in which:

FIG. 1 is a perspective view of a base constructed in accordance withthe principles of the present invention, together with an airconditioning heat exchanger unit mounted thereon;

FIG. 2 is a plane view of the base of FIG. 1;

FIG. 3 is a sectional view of the base of FIGS. 1 and 2 as seen alongthe line 3-3 of FIG. 2; and

FIG. 4 is a perspective view illustrating in part, the presentlypreferred method and apparatus for making the base of FIGS. 1-3.

7 DETAILED DESCRIPTION Referring now to FIG. 1 there is depicted a heatexchanger unit 10 of a particular type 'used in residential airconditioning systems, which unit is mounted atop pad or base which isgenerally designated and is constructed in accordance with the presentinvention. The base 20, as is the normal practice, is situated on theground 14 and is exposed to the elements remote from the structure to becooled.

As is better seen in FIG. 2, this particular base 20 is generally squarein overall shape. Although here shown -for definiteness as square othershapes, such as round or rectangular, to conform to the shape of theunit 10, may be employed without departing from the present invention.The base 20 is pre-manufactured by being pre-casted as will be explainedbelow.

The base 20 has an upper or top surface 22 which is generally planar orflat for receiving the unit 10. This surface preferably has mountingbolts 24 projecting from it to receive the unit 10 and affix it to thebase 20. The bolts 24, as are better seen in FIG. 3, are preferably setbelow the surface 22 and captivated within the body of the base 20.

Also visible on the surface 22, as can be seen in FIGS. 1-3, is a bubblelevel 26 which is also preferably captivated in the body of the base 20.This bubble level 26 is per se old and may be of the conventional typeused, for example, in static wheel balancing machines, but shouldcontain a liquid such as alcohol that will not easily freeze. This typeof level has, as is best seen in the side view of FIG. 3, a dome-shapedtop. It may be positioned anywhere on the upper surface 22 but ispreferably positioned, as shown, in a corner so as to be visible afterthe unit 10 is affixed to the base 20.

As best seen in FIG. 3, the base 20 includes a generally flat bottomsurface 28 for sitting on the soil and side walls 30 between the top andbottom surfaces 22 and 28. These walls 30 are slanted or inclinedoutward from the top surface 22 toward the bottom sur face 28 to form anangle a with a vertical plane. This particular construction aids in themanufacture of the base 20, as will be explained below in connectionwith FIG. 5,as well as in the seating of the finished pad on the ground.The angle a is preferably about 22.

As is also best shown in FIG. 3, and in accordance with the primaryfeatures of the present invention, the body of the base 20 is verticallystradified and includes a thin upper layer 32 adjacent to and formingthe surface 22, of essentially conventional concrete-cured mixed sandaggregate, cement, and water. The remainder zone 34 of the body of thebase, in accordance with the present invention, is formed of vermiculiteaggregate concrete, and includes a generally planar and horizontallyextending reinforcing metal wire screen 36 which is positioned in aplane generally parallel to and about half-way between, the top andbottom surfaces 22 and 28. v 4

The reinforcing screen 36 is preferably expanded metal screening withdiamond shaped openings bounded by metal ribbon segments slanted orangled to the plane of the screen. One suitable type of such screeningis the type used as lathing in the construction of plaster interiorfinished room walls.

The composition and manner of making the base 20 can be illustrated bymeans of example with the use of the illustration of FIG. 4. In thatFigure a pan shaped forming fixture 40 is shown mounted on a shankingtable 42. The form 40 includes depressions 24 and 26' for receiving thebolts 24 and the level 26. These latter fixtures are preferably mountedin their respective depressions in the empty form 40 by means of aremovable binder such as wax. Next pre-soaked vermiculite aggregate,cement and water are mixed and poured into the form which is shaking orvibrating form, as indicated by the arrows 44. Coloring, e.g. green, ifdesired may be added at this point in the process. Sand is then added,which because of its higher specific gravity than the vermiculite, willgravitate to the bottom of the form to eventually form the top layer 32of the finished base 20. After this, the reinforcing screen 36 isimpressed into the still fluid mixture to its desired position. Theouter dimensions of the screen may be sized to have it fit against thesloping side walls of the form 40 at the proper depth.

The proportioning of the dry ingredients by weight is preferably aboutthe following: two units of vermiculite to 10 units of cement to fiveunits of sand. By volume the vermiculite provides the bulk of the base.

As a particular example, two pounds of vermiculite plus 10 pounds ofcement and five pounds of said will yield a 2 inch thick square padabout three feet by three feet of a cured weight of about 20 pounds. Asimilar sized base of conventional construction would weigh from four orfive or more times as much.

After the base has set, it is removed from the form 40 and, preferablyafter curing, is dipped in silicone or wax to seal it. The onlyadditional preparation required is to remove the protective wax from thebolts and top of the bubble level. When this is done the base is readyfor installation.

As should now be clear, a new and improved ground base for heatexchanger units has been described that is lighter in weight thanprevious bases, easier in handling, less expensive to ship, less likelyto be dropped or broken and which provides for greater sound'deadeningand vibration dampening than prior pads.

The ability of the vermiculite concrete bottom. to adapt to shifting andslightly irregular soils without fracturing, insures a better effectiveuse-life for theinstalled base. The use of the permanent bubble level,while not necessarily for the practice of the broader aspects of thepresent invention, provides for easy installation and will give awarning to the user of shifting soils or uneven settling of theinstalled base and unit. The inclined side walls, while also notnecessary for the practice of the invention in its broader aspects, hasthe further advantages of easing removal of the base from the form andof preventing or lessening horizontal shifting of the installed base andunit.

While particular embodiments of the invention have been shown anddescribed, it will be obvious to those skilled in the art that changesand modifications may be made without departing from the invention inits broader aspects and, therefore, the aim in the apsaid structurehaving metal internal reinforcements positioned between its top andbottom surfaces;

said structure being composed primarily of concrete employingvermiculite as its primary, by volume, aggregate, and having saidvermiculite concrete form said bottom surface and, at least, the majorpart of said structures thickness above said bottom surface;

said base formed with a thin layer of hard concrete at its top surface;

said base defining inclined side walls between the marginal segments ofsaid top and bottom surfaces which walls are inclined outward from themarginal top'surface to the bottom surface, and

said base having affixed therein bolts for affixing the heat exchangerunit to said base which bolts are head mounted into said base with stemsthat project outwardly from said top surface.

2. The heat exchanger unit ground base as defined in claim 1, wherein:

said base has, affixed on its upper surface, a bubble level to aid inleveling during installation of the base and of any heat exchanger unitthereon.

3. A pre-manufactured heat exchanger unit ground base comprising:

form said bottom surface and, at least, the major part of saidstructure's thickness above said bottom surface;

said base formed with a thin layer of hard concrete at its top surface;

said concrete being formed with dry weight portions of approximately twounits of vermiculite to five units of sand to ten units of cement; and

said reinforcement is a generally planar metal screen affixed generallyparallel to and approximately equidistant from said top and bottomsurfaces and comprising an expanded cut-and-formed metal sheet whichsheet defines a plurality of small openings bounded by metal ribbonsegments whose planes are inclined to the plane of the screen.

4. The ground base for a heat exchanger unit as defined in claim 3,wherein:

said base has, affixed on its upper surface, a bubble level (26) to aidin leveling during installation;

said base defines inclined side walls (30) between the marginal segmentsof said top and bottom surfaces which walls are inclined outward fromthe marginal top surface to the bottom surface;

said base has affixed therein means (24) for affixing the unit to saidbase which means project outwardly from said top surface;

said means for affixing are bolts, head mounted into said base withstems projecting out of the top surface; and

said base is dip-sealed in a concrete sealant.

1. A pre-manufactured heat exchanger unit ground base comprising: aunitary structure having a generally parallel and generally flat top andbottom surfaces; said structure having metal internal reinforcementspositioned between its top and bottom surfaces; said structure beingcomposed primarily of concrete employing vermiculite as its primary, byvolume, aggregate, and having said vermiculite concrete form said bottomsurface and, at least, the major part of said structure''s thicknessabove said bottom surface; said base formed with a thin layer of hardconcrete at its top surface; said base defining inclined side wallsbetween the marginal segments of said top and bottom surfaces whichwalls are inclined outward from the marginal top surface to the bottomsurface, and said base having affixed therein bolts for affixing theheat exchanger unit to said base which bolts are head mounted into saidbase with stems that project outwardly from said top surface.
 2. Theheat exchanger unit ground base as defined in claim 1, wherein: saidbase has, affixed on its upper surface, a bubble level to aid inleveling during installation of the base and of any heat exchanger unitthereon.
 3. A pre-manufactured heat exchanger unit ground basecomprising: a unitary structure having a generally parallel andgenerally flat top and bottom surfaces; said structure having metalinternal reinforcements positioned between its top and bottom surfaces;said structure being composed primarily of concrete employingvermiculite as its primary, by volume, aggregate, and having saidvermiculite concrete form said bottom surface and, at least, the majorpart of said structure''s thickness above said bottom surface; said baseformed with a thin layer of hard concrete at its top surface; saidconcrete being formed with dry weight portions of approximately twouNits of vermiculite to five units of sand to ten units of cement; andsaid reinforcement is a generally planar metal screen affixed generallyparallel to and approximately equidistant from said top and bottomsurfaces and comprising an expanded cut-and-formed metal sheet whichsheet defines a plurality of small openings bounded by metal ribbonsegments whose planes are inclined to the plane of the screen.
 4. Theground base for a heat exchanger unit as defined in claim 3, wherein:said base has, affixed on its upper surface, a bubble level (26) to aidin leveling during installation; said base defines inclined side walls(30) between the marginal segments of said top and bottom surfaces whichwalls are inclined outward from the marginal top surface to the bottomsurface; said base has affixed therein means (24) for affixing the unitto said base which means project outwardly from said top surface; saidmeans for affixing are bolts, head mounted into said base with stemsprojecting out of the top surface; and said base is dip-sealed in aconcrete sealant.